1. Field of the Invention
The invention relates to a rear shielding shell for a plug electric connector, particularly to a rear shielding shell for a Universal Serial Bus (USB) plug connector which, in addition to being able to shield contacts and leads of a cable in connection with the contacts, can fix the cable in position.
2. The Prior Art
A variety of types of plug connectors are shown in Taiwan Patent Application Nos. 81205708, 82205124, 83212053, 83215969, 79201839, 80203806, 83212623 and 83214112.
FIG. 1 shows a conventional USB plug connector 500 of the type that the present invention is concerned and intends to improve. The USB plug connector 500 generally consists of a dielectric body 510, a number of contacts 520 mounted to the dielectric body 510, a front shielding shell 525 defining a pair of latching legs 530, a cable 540 having four leads 600 each being clamped by a corresponding contact 520, a spacer 560 for suitably spacing the leads 600 from each other, and a rear shielding shell 570. The rear shielding shell 570 defines a pair of elongated holes 572 (only one being shown). The latching legs 530 are extended through the holes 572 to engage with the rear shielding shell 570 so that the front and rear shielding shells can be connected to entirely shield the leads 600 and the contacts 520, and a guiding sleeve 574 through which the cable 540 can be extended into an inner space defined by the connected front and rear shielding shells 525, 570. After the components as shown in FIG. 1 are assembled, they are subjected to a plastics injection molding process to form a gripping portion (not show) thereon.
The conventional USB plug connector is found to have the disadvantages as set forth below.
First, the guiding sleeve 574 is not formed with a means which can securely engage with the cable 540 to fixedly locate the cable 540 in position. This brings about that the assembling operations for manufacturing the plug connector 500 cannot be carried out smoothly.
Furthermore, since the cable 540 is connected to the connector 500 only by the clamping force of the contacts 520 acting on the leads 600, when a large force is exerted to pull the cable 540 away from the connector 500, a disengagement between the leads 600 and the contacts 520 may occur.
Finally, in order to facilitate the insertion of the cable 540 through the guiding sleeve 574, the guiding sleeve 574 is formed to have a diameter which is sufficiently larger than that of the cable 540. This brings about that a gap is formed between the guiding sleeve 574 and the cable 540, wherein the plastics material for forming the gripping portion (not shown) may flow into the inner space between the front and rear shielding shells 525, 570 via the gap to cause the gripping portion (not shown) to have a thickness less than a predetermined thickness.
Therefore, an objective of the invention is to provide a rear shielding shell for a plug connector, particularly for a USB plug connector. The rear shielding shell has a guiding sleeve for guiding an extension of a cable through the rear shielding shell. The guiding sleeve is formed with a retaining portion whereby the cable can be fixedly located in position.
Another objective of the invention is to provide a rear shielding shell for a plug connector, particularly for a USB plug connector. The rear shielding shell has a guiding sleeve for guiding an extension of a cable through the rear shielding shell. The guiding sleeve is formed with a retaining portion whereby the cable can be securely connected to the connector.
A further objective of the invention is to provide a rear shielding shell for a plug connector, particularly for a USB plug connector. The rear shielding shell has a guiding sleeve for guiding an extension of a cable through the rear shielding shell. The guiding sleeve is formed with a retaining portion whereby plastics material for forming a gripping portion of the plug connector is prevented from flowing into an inner space between the rear shielding shell and a front shielding shell via a gap between the guiding sleeve and the cable.